"But they will eventually come down, right?"
Come down where? Not necessarily. They MIGHT come down, if they travel close enough to some other object out there in space. If not, they won't ever come down anywhere.
Did you think they were coming back to Earth, mlcnnn? They're gone into the far reaches of our galaxy, probably never to touch down anywhere again.
You know that the universe is mostly empty, right? All those little lights in the sky are unimaginably far apart from each other...so far that an object traveling outside of one solar system is very, very unlikely to ever encounter another solar system.
So, it's bye-bye for those craft. They're galaxy-wanderers now, and probably forever. That little plaque on one of them, with the cute drawing of the naked man and woman holding hands, will most likely never been seen by any intelligent life form. A bit sad, but the universe is huge, and we are so small. Makes you feel kind of insignificant, huh?
I must go for the day. Perhaps we'll encounter each other once again.
"If not, they won't ever come down anywhere."
How can you prove that?